<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>变量</title>
</head>
<body>
    <script>
        var num1 = 070;
        var num2 = 0x1f;
        console.log(num1,num2);

        console.log(isFinite(21));
        console.log(isFinite("hello world"));
        </script>
</body>
</html>